Yes you can.
I built my original X2 mill in 2005 with Gecko G201 drives and NEMA 34 450oz.in motors. The exact set up was transferred to my BF30 mill which is probably 5 times the weight and the system works flawlessly. Whether that's the right way to do it is a matter of opinion. If you wished to upgrade to a larger mill, you might find it easier and more profitable to sell the smaller machine as a turn-key CNC solution and start again on the big mill. I guess it depends on your circumstances.